Whats the difference between the Omega 1000/9000 juicer and the Omega 4000?

The omega 1000/9000 are centrifugal juicers, which work much like a washing machine on the spin cycle, constantly spinning around the pulp to extract the juice. This causes it to get a bit better yield than the 4000. Although sometimes like washing machines get "off balance".. this can happen with the Omega 1000/9000 as well in some circumstances- (if it gets too full for example).. The juice may then "walk" across the table. The 4000 on the other hand "ejects" the pulp into a pulp catch bin, which makes it easier and faster to use, in our opinion. The 4000 and 9000 have a 15 yr warranty, and the 1000 has a 10 year warranty. We prefer the 4000 since its easier to clean, and faster to use. The 4000 will juice citrus, as will the 9000 and 1000 WITHOUT an attachment. Oranges, Grapefruits, and tangerines must be peeled, then can be put into the juicer.. (there are toxic chemicals in the skin of those citrus fruits).